Global Environmental changes and Metacommunities: Species interactions and spatial dynamics

Informations

Funding country

France

Acronym

GEMS

URL

-

Start date

1/1/2014

End date

-

Budget

209,924 EUR

Fundings

Abstract

To preserve the integrity of biodiversity functioning under the current global environmental changes (GEC) requires the availability of valuable tools to assess the efficiency of proposed management actions, which need to rely on a thorough knowledge of the relationship between the environmental conditions and the functioning of biodiversity at a variety of integration levels, from genes to ecosystems. These tools are currently mostly simulation platforms, whose efficiency strongly depends on their realism. Several over-simplifications however currently reduce this realism: GEC drivers like habitat fragmentation, climate change and so on, are considered separately from each other; species interactions are largely ignored; and evolutionary or plastic changes in key traits are not considered. The aim of GEMS is to clear these hurdles. In GEMS, we will consider how habitat fragmentation and climate change, two main drivers of GEC in temperate regions that are currently considered in isolation, in combination affect the functioning of metacommnities. Rather than to focus on putative responses of disconnected populations, considered outside their network of inter-species interactions (competition, predation, etc.), we will consider explicitly these species interactions and the dispersal of individuals through fragmented landscapes. GEMS will thus consider local effects at the population level, indirect effects acting through species interactions at the community level, and landscape-scale effects acting through modified dispersal among local populations at the landscape level, that combined give rise to metacommunity functioning. To that purpose, we will first identify along gradients of fragmentation and climate the modifications in key processes of metacommunity functioning (dispersal, phenology and population dynamics) for three species in strong interaction: a specialized herbivore, its host plant and its specialized parasitoid. The impact of landscape fragmentation and climate on dispersal will be addressed by landscape genetics, with the aim to identify tipping points in the responses of the three interacting species. In parallel, local phenology and dynamics will be recorded in populations of the three species along the two environmental clines, to see whether fragmentation and climate cause temporal mismatch of interacting species or modify their strength. Then, to highlight the processes behind the observed responses, we will manipulate the environment in controlled conditions. Using climate chambers and large-scale mesocosms (the Metatron), we will identify which of selection or phenotypic plasticity sustains the patterns of response, by which traits these changes in metacommunity functioning are mediated, and how the response at each trait is constrained by the other traits. Finally, we will integrate how the elemental responses observed combine by using a metacommunity model. With this model, we will also investigate what could be the response of this metacommunity to projected climate change, future landscape fragmentation, or mitigation scenarios, and their interactions. Altogether, GEMS will thus provide both fundamentals insights on metacommunity functioning and have direct conservation applications by providing a realist tool to help decision-making in the conservation of biodiversity.